Fixes #4958 Truncate printed stdout if it contains non-printable characters

lib/ansible/utils/string_functions.py

@@ -0,0 +1,7 @@
+def isprintable(instring):
+    #http://stackoverflow.com/a/3637294
+    import string
+    printset = set(string.printable)
+    isprintable = set(instring).issubset(printset)
+    return isprintable
+